Technical Field
The present invention relates to a light emitting apparatus that includes a light transparent member that allows light from a light emitting device to pass through the light transparent member, and a method for producing the light emitting apparatus.
Background Art
Semiconductor light emitting devices are small and highly effective in power consumption, and emit vivid color light. In light emitting devices composed of a semiconductor element, there are no concerns about bulb burnout and the like. In addition, semiconductor light emitting devices have features such as excellent initial drive characteristics, and resistance to vibration or light ON/OFF repeats. Also, light emitting apparatuses have been developed that include a light emitting device and a wavelength conversion member and can emit light of various colors. In such light emitting apparatuses, the light emitting device emits source light, while the wavelength conversion member can be excited by the source light to emit light of color different from the source light. Combination of the source light and the light of converted color provides light emission of various colors based on additive color mixture principle. Since semiconductor light emitting devices have these excellent features, light emitting devices such as light emitting diodes (LEDs) and laser diodes (LDs) have been used as various types of light sources. Particularly, in recent years, attentions are given to semiconductor light emitting devices as replacement lighting sources for fluorescent light, and next-generation lighting with lower power consumption and longer life than fluorescent light. Accordingly, semiconductor light emitting devices are required to further improve light emission output and light emission efficiency. In addition, it is desired to provide a semiconductor light emitting device that serves as a high-luminance light source such as a car headlight and a floodlight.
One example of such semiconductor light emitting devices can be given by Patent Document 1 that discloses a light emitting apparatus 100. FIG. 10 shows a cross-sectional view of the light emitting apparatus 100. The light emitting apparatus 100 includes an LED device 102, and a case 103 that is provided with the LED device 102. The case 103 has an opening on a light outgoing side. The LED device 102 is mounted in this opening. Also, the opening of the case 103 is filled with a coating material 111 containing light reflective particles 111A. The coating material 111 covers the external area of the LED device 102 except a light outgoing surface 105A.
In addition, a sheet-shaped phosphor layer 110 is arranged on the external surface of the filling coating material 111, and on the light outgoing surface 105A. The phosphor layer 110 is composed of resin containing a phosphor such as YAG (Yttrium Aluminum Garnet), which can absorb light emitted from the LED device 2 (blue light) and be excited by the absorbed light to emit wavelength conversion light (yellow light). The phosphor layer 110 is arranged to cover the entire light outgoing surface 105A of the LED device 102, and has a light emission surface 110A exposed on the light outgoing side. The primary light from the LED device 102 (blue light) is mixed with the secondary light (yellow light) that is converted in wavelength from a part of the primary light. As a result, white light is obtained from the light emission surface 110A.    Patent Document 1: Japanese Patent Laid-Open Publication No. 2007-19096    Patent Document 2: Japanese Patent Laid-Open Publication No. 2002-305328